1. Field of the Invention
The present invention relates to a power supply device, and more particularly, to a power supply device capable of quickly disconnecting a supply of power when a load is short-circuited.
2. Description of the Related Art
Recently, various electronic devices, meeting various user needs, have been variously implemented. These electronic devices may employ power supply devices supplying operating power thereto in order to achieve desired functions.
Typically, a power supply device may employ a switching mode power supply (SMPS) scheme, having advantages such as power conversion efficiency, miniaturization and the like.
Typically, a power supply device has a configuration for interrupting the supply of power when a load is short-circuited.
There are a variety of methods for interrupting a supply of power when a load is short-circuited. For example, there is a method in which a current sensing circuit is added to an output voltage loop and current flowing through the loop is sensed so that it may be determined that a short-circuit has occurred in output voltage if sensed current is above a predetermined value. In addition, there is a method in which current flowing through a switching element for transferring power is sensed, to interrupt the switching operation.
These methods operate separate protection circuits so that the protection circuits take certain actions.
However, there may be a delay until the protection circuits operate, and additional components are required, which become an obstacle for high-density design. Further, such protection circuits may cause design costs to be increased.
Patent Document 1 discloses a device for protection against shorts in switching power, and Patent Document 2 discloses a safety device for preventing shorts. However, the Documents do not disclose rapidly protecting a power supply device when a load is short circuited.